In general, a refrigerator is an apparatus for storing objects to be kept in a fresh state for a long period of time using cool air supplied into a storage compartment. The cool air supplied into the storage compartment is created through heat exchange with a refrigerant. The cool air supplied into the storage compartment is uniformly distributed throughout the storage compartment by convection so that foodstuffs can be stored at a desired temperature.
The storage compartment is defined in a main body that forms the appearance of the refrigerator. The storage compartment is open at the front thereof such that foodstuffs can be received through the opening. A door for opening or closing the storage compartment is mounted at the front of the storage compartment. The door is hinged to the main body to open or close the storage compartment.
In order to prevent the leakage of cold air to the outside and to ensure close contact between the main body and the door, a gasket is disposed between the main body and the door.
The gasket is typically magnetic in order to improve sealing performance.
In order to open the door automatically, it is necessary to provide force not only to rotate the door but additionally to separate the gasket from the main body.
In conventional refrigerators, a technology of connecting a motor to a hinge unit of a door is used. In this case, since there is a significant difference between the force required to separate the gasket and the force required to rotate the door, an excessively large actuator is necessary, which is inefficient. In addition, since the refrigerator is required to have increased space in order to accommodate the large actuator, it is difficult to provide the increased space without compromising the size or thermal insulation performance of a conventional refrigerator.
Furthermore, since a drive unit and an opening and closing unit are connected to each other even when the door is manually opened, there are problems in that a lot of power is required for a user to manually open the door and in that the drive unit may be broken while a user opens the door.
In addition, when an opening or closing command is input through an input unit while a user is holding objects with both his/her hands under the condition that the door is opened, it is impossible to close the door.
Furthermore, when there is an extraneous object or a user blocking the door while the door is automatically opened or closed, the motor for driving the door may be overloaded, and the user may be injured.